The invention is directed to a device a device for the sharpening, grinding and polishing of dental, parodental and/or surgical instruments of the type indicated in the preamble of claims 1, 2 or 10.
The maintenance of medical instruments, e.g. dental, parodental and/or surgical instruments, which are not provided for disposal after use, is an essential requirement for a successful therapy. Maintenance of these instruments comprises, among others, sharpening, renewed cutting, grinding and polishing of instruments which have become blunt or notched by usage or have become unfit for optimum use due to other influences. Particularly in the field of dentistry, it is often tried to re-grind or re sharpen precious instruments such as scalers, curettes, gingival border beaters, excavators, carving instruments, rasps, root lifters, scissors, sharp spoons etc. so that these instruments can be successfully used several times.
For avoiding bothersome manual grinding, there are used hand- or motor-driven grinding devices. However, because of the restricted variabilty of such devices, only certain instruments can be treated successfully. Among these are scalers, curettes, Hoe scalers and gingival border beaters.
EP-A-0 307 740 is directed to a device for the sharpening of the cutting edges of scalers clamped in a holding device and of other parodental instruments by means of a motor-driven grinding disk. By the device described therein, a re-grinding of the cutting edge of parodental instruments shall be reproducible, i.e. be feasible at identical grinding angles and an identical grinding pressure during each use. The grinding body to be used for sharpening, provided as a grinding disk, is rotatably supported on a bearing block resting on a support structure. The support structure comprises two support arms being articulated to the bearing block and having their free ends articulated to each other by a connecting member. The four joints between the bearing block, the support arms and the connecting member form a parallelogram. The ,support structure is arranged for rotation so that the grinding body performs a circular movement upon rotation of the support structure. The support structure projects from an opening in the upper side of a base housing having two holding arms arranged thereon, with the clamping device being supported for rotation about a horizontal axis between said arms. The connecting member connecting the two support arms of the support structure is pivotable. Through a horizontally displaceable sliding block, abutting a stationary control member and being displaced while scanning the control surface thereof during rotation of the support structure, the connecting member is pivoted about its pivoting point. At the same time, while the grinding body is in abutment on the instrument, the support arms of the support structure move relative to each other, resulting in a pivoting of the bearing block and thus a change of the inclination of the grinding surface of the grinding body. By controlling the inclination of the grinding surface in this manner, grinding can be performed on instruments as e.g. scalers or curettes wherein the inclination angle of the grinding surface at the lateral faces of the instrument and that at the acute end have to be selected differently.
The support structure of the known grinding machine can be rotated about a stationary vertical axis only. Instruments wherein the grinding body must be longitudinally displaceable along the cutting edges thereof for sharpening the instrument over its whole length, can be treated only in a restricted manner or not at all by the known device. Further, the clamping means allows clamping of only a limited number of different instruments.